Grinding and polishing machine



April 30, 1929. J. a. BAILEY GRINDING AND POLISHING MACHINE Filed Feb. 18, 1924 Patented Apr. 30, 1929.

UNITED STATES PATENT OFFICE.

JOHN B. DAILEY, F DETROIT, MICHIGAN, ASSIGNORYIO GENERAL MOTORS CORPO- BATION, 0F DETROIT, MICHIGAN, A CORPORATION OF.DELAWARE.

GRINDING AND POLISHING NIACEIIINE.`

Application site February is, 1924. sensi no. 693,562.

The invention relates to machines for grinding or polishing and while in some respects of more generic application itis especially concerned with machines designed for l preparing specimens for metallographic investigations.

At the present time it is customary to control or check the quality and characteristics of metals and alloys used for various industrial purposes and to determine the e'ect of heat treatments and other operations affecting the Ainternal structure of the metal by microscopic or photographic investigation y of specimens showing the cross section of the metal or article in question. For such investigations it is necessary that the specimens be very carefully ground and polished.

Where extensive manufacturing operations are carried on as, for example, in a large automobile manufacturing plant, it isnot unusual for a single metallurgical testing laboratory tobe required to prepare and examine hundreds of specimens daily, and the prepai'ation of test sections with the necessary rapidity becomes a task of considerable importance.

The object of my invention therefore is, in general, to improve the construction and operation of machines ofthe type used in 430 producing smooth plain surfaces on objects usually of relatively small dimensions, and to facilitate the process of polishing, particularly where a large number of objects are to be operated u on.

Further obiects and advantages will appear from the following description taken in connection with the accompanying drawings illustrating one embodiment of the 1nvention, and in which:

Fir'. 1 is an elevation partly in section, showing a plurality of polishing units arranged for convenient operation and associated with suitable water supply and sewerage connections; I

Fig. 2 is a plan view of one of the units;

Fi 3 is a' vertical section on line 3--3 of Fig. 2;

Fig. 4 is a detail vertical section on line 1&4 of Fig. 3; and

Fig. 5 is a horizontal section on line 5--5 of Fig. 1.

Referring to the drawings, I have shown in Fig. 1 a group of three grinding or polishing units associated in a single assemblage, which arrangement I have found highly satisfactory for convenient and expeditious operation. The assemblage includes a stand or bench comprising` frame members 10, 11 supporting a top 12, which may be of stone, wood. or other material suitable for the purpose. The top 12 is provided with circular apertures within whichmay be mounted metal rings 13 for supporting the individual grinding or polishing units. rIhe top is also provided with basins or wash receptacles 14 which ma?)7 be connected to a pipe 15 leading to a suita le sewer connection. Each of the respective grinding or polishing units comprises a frame or bracket having avertically extending portion 16 and a horizontal portion 17. The vertical ortion 16 is shaped to receive the base 18 otpan electric motor 19, the motor being secured to the bracketby screws or bolts 20. The armature shaft of the motor indicated at 21, therefore, extends substantially in a vertical direction.

'lhe'liorizontal portion 17 of the motor bracket is provided with a cup shaped ortion 22 with an opening in the bottom t rough which extends a spindle 23. Surrounding the spindle within the cup shaped portion 22 are arranged anti-friction lateral bearings 24, 25, and an anti-friction thrust bearing 26. Above the cup shaped portion 22 the spindle 23 is provided with-a collar 27, the lower surface of which servesas a shoulder to su port the spindle and the parts carried there ly upon the bearings 24, 25 and 26. A fe twasher 28 and a sheet metal cap 29 may be mounted upon the spindle above the antii'ction bearing, as shown, to cover the upper end of the cup 'shaped bearing receptacle in the portion 22 and thereby protect the anti-friction bearings from dust, moisture,

etc. A lubricant receptacle 30 may also be provided communicating with the cup shaped bearin(1 cavity to supply lubricant thereto as desire Above the collar 27 the spindle ,23 is screw threaded as at 31 to fit a correspondin ly threaded hub 32 on the polishing disk or ta le 33. The table when in position on the spindle 23 is therefore supported in an approximately horizontal position, and when the spindle is driven by the motor 1'9 thetable will be rotated in an approximately horizontal plane.

It will be understood, however, that the exact position ofthetable 33 may be varied to suit the convenience ofthe operator and the character of the work.

The upper' surface of the table 33 will be provided with suitable means for performing the desired operation of grinding or polishing. In the 4form illustrated in the drawing the table is provided with a fabric cover 34, which may be held in position by a hoop 35. The character of the fabric will depend upon the nature of the articles to be ground -or polished, the character of the abrasive used, and other conditions, as well known to those skilled in this art. In the assemblage of units illustrated in Fig. 1 it is preferred to use for the cover 34 of the first unit a coarse material such as canvas, while the cover 34 of the second unit will be of afiner material, as of broadcloth, and the cover 34 ofy the third unit of still finer material. Abrasives of corresponding degrees of Iineness will of course be employed on the successive tables.

The horizontal portion 17 of the motor bracket is secured as by bolts 36 to the lower side of a casing member 37, of generally an nular form which performs the function both of a support and a shield. This member may be cast or otherwise formed of metal, and is provided at its periphery with a flange 38 which may be rigidly secured to the bench 12 or tothe ring 13 as by screws 39. The bottom portion of the member 37 extends upwardly as at 4() to form a sleeve surrounding the spindle 23 and preventing the overflow of water or other liquid within the member 37 around the s indle and its bearings; The upper edge o the member 37 is directed inwardly as at 41 to form a iange adapted to catch liquid or other material thrown against the outer walls of the shield and preventthe same from escaping over the u' per edge of the shield. At a suitable point 1n the bottom of the shield is provided a drainage aperture 42, from which a pipe 43 leads to a suitable sewer` connection, as lllustrated in Fig. 1. The pipes leading from the successive polishing units are connected by a header 44 and apipe connection 45 to a drain pipe 15.

In order to transmit motion from the armature shaft 21 to the spindle 23 the said shaft is provided with a coupling sleeve 46 keyed to the armature shaft to rotate therewith as at 47, and prevented from movement longitudinally of the shaft by set screw 48. An anti-friction bearing 49 may be provided between this coupling sleeve and the frame of motor 19, thereby assisting in supporting the weight of the armature shaftand the parts mounted thereon. A similar coupling sleeve 50 is keyed as at 51 to the vlower end of the spindle 23. A disk or ring 52 of flexible or yieldable material, as leather, is interposed between the adjoining faces of the coupling disks or sleeves 46 and 50- Holes 53 are formed in the ring 52, and axially projecting pins 54, are seated in apertures 1nv the sleeves 46, 50, respectively, in position to engage in the holes 53; the pins 54 carried by sleeve 46 engaging in one pair of holes 53 on opposite sides of the spindle 23, while the pins 55 carried b sleeve 50 engage in the other pair of ho es intermediate those in which the pins 54 engage. It will be seen, therefore, thatthe transmission of motion from the motor shaft or the coupling sleeve 46 to the spindle 23 through the coupling 'sleeve 50 takes place through an intermediate flexible or yielding member, which serves to relieve the parts of shock to a certain extent and also permits of assemblage vwithout the accurate alignment of the spindle and armature shaft that would otherwise be required. It will be noted that the couplin provided at the points 54, 55 and the lexilile ringor disk 52 is of a rea'dily detachable character, and hence the motor may be withdrawn from` the spindle by endwise sliding movement upon the removal of the securing means 20, and assemblage of the motor and spindle is also easily performed.

It will also be noted that the respective units comprising the supporting ring and shield 37 aud the bracket 16, 17 with the parts assembled thereon may be mounted upon the bench by merely inserting the assemblage from above into the apertures on the bench. The manufacture and assembling of the apparatus is, therefore, greatly facilitated since the respective units can be assembled at the convenience of the workman in a machine sho or at thefactory, and may then be readily installed at the place of use by ordinary unskilled workmen. At the same time the parts may be readily disassembled for repair olr' u1eplacement without requiring special su When the operation performed upon the machine requires the suppl of water or other liquid to the rotating tables 33, such liquid may be supplied by ipes arranged to discharge upon the sur ace of the tables. In the assemblage illustrated in Fig. 1, where water is utilized, pipes 56 may be mounted upon the bench in position to dischar water upon the tables, the flow of water belng controlled by valve means as at 57. The discharge portion of pipe 56 is preferably ar- Y ranged to swing about the axis of the vertical portion so that the pi e may be positioned where it will not inter ere with the grinding o eration when a supply of liquid is not desired. Similar pipes 58 ma be mounted upon the bench in position to y ischarge water into the basins or receptacles 14, the water being supplied both to pipes 56 and 58 from a pipe 60 connected to a suitable source of supply 59. In the arrangement illustrated the basins 14 and pipes 58 are arranged between the respective polishing units in such position that an operator enga. in polishing a specimen in one of the units may readi ly have access to one of the basins forthe purpose of washing the specimen upon which he is working. The provision of a plurality of units provided wlth polishing means of successive adations of iineness -and with kabrasives o similar grades enables the work ber vof workmen, for example, three in the as-4 semblage illustrated, to engage at the same time upon the work of polishing specimens, each workman receiving the specimen from the preceding workman, and thus enabling the successive operations to be completed most expeditiously.

The motor 19 may be controlled by any usual or suitable control devices. As'i1lustrated current is supplied b conductors 61, the actuation ofeach motor eing controlled independently ofthe others as by a switch 62. Additional means of usual character such as rheostats may be employed to vary at will the speed of each motor.

vWhile I have describedl herein specific de tails of construction, it will bel understood that changes may be made without departing from the spirit and scopeof the invention,

and .therefore I do not desire to be restricted l by reason of the specific disclosure, except as required by the language of the appended claims, in vview of the prior art.

I claim:

v 1. In a polishing machine, a support having an aperture therein, a shield member mounted upon said support and positioned ber, a spindle adapted to support said table,Y

bearings for said s indle carried by said bracket and arranged) to support thespindle wholly from the bracket, and a motor support by said bracket andY operatively connected to said spindle. I

3. In a grinding or polishing machine, a shield member provided with means whereby it'may be secured to a bench `or stand,l a bracket supported b and depending from the said member, a tablb positioned within said member, a spindle u n whichvsaid table is supported, ybearings or said spindle carried by said bracket independently of the shield member, and an electric 'motor' also 'carried by said bracket and having its armature shaft approximately in alignment with said spindie, and operatively connected thereto.

p In testimony whereof I aliix my signature.

JoHNpB. BAILEY.. 

